Endoscope system including endoscope and disposable protection cover

ABSTRACT

In an endoscope system including an endoscope having an insertion section insertable into a cavity under inspection and an operation section having at least one operation switch, said operation section being connected to a proximal end of said insertion section and a disposable protection cover having an insertion section cover for covering said insertion section of the endoscope and an operation section cover for covering said operation section of the endoscope, said insertion section cover includes a forceps channel through which existing forceps for use in ordinary without-cover endoscopes can be inserted. An inner diameter of the forceps channel is determined to be slightly larger than an outer diameter of most frequently used forceps or standard forceps whose number shows a peak in the outer diameter series of the forceps.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an endoscope system including anendoscope having an insertion section which is insertable into a cavityunder inspection and an operation section to which a proximal end of theinsertion section is connected, and a disposable protection cover havingan insertion section cover for covering the insertion section of theendoscope and an operation section cover for covering the operationsection of the endoscope.

2. Related Art Statements

An endoscope system has been widely utilized for providing diagnosticand therapeutic indications for coeliac cavities of patients and forinternal inspection of mechanical structures. To this end, various kindsof endoscopes have been developed. For instance, in order to inspect ortreat the oesophagus, stomach and duodenum, upper endoscopes have beenutilized. Further, colonoscopes have been developed to examine colons,and sigmoidoscopes have been proposed to inspect rectums and sigmoidcolons. When the endoscope is used, an insertion portion of theendoscope has to be inserted into a cavity of a patient, so that theouter surface of the insertion section of the endoscope is contaminatedwith living tissues and liquids. Such a contaminated endoscope could notbe successively used for other patients. Therefore, once the endoscopeis used to diagnose and/or treat a patient, it is necessary to clean andsterilize the endoscope. Of course, the cleaning of the endoscoperequires a substantial amount of time and during this cleaning time, itis impossible to perform the endoscopic procedure by using thisendoscope. In order to mitigate such idle time, it is necessary toprepare a large number of endoscopes. However, endoscopes are ratherexpensive, so that it is practically difficult to prepare a large numberof endoscopes, particularly in a small hospital or clinic. Therefore, inalmost all hospitals and clinics, in practice, after the endoscope hasbeen used for examining or treating a patient, the endoscope isimmediately cleaned. Typically, this cleaning requires several minutes(up to ten minutes). In order to effect complete washing andsterilization, the cleaning has to be performed for several tens ofminutes.

Further, the endoscope has various channels such as an air channel, awater channel, a suction channel, and a forceps channel which extendalong the insertion section from a proximal end to a distal end thereof,and these channels, except for the forceps channel, are connected viatubes to respective devices such as an air supply pump, a water supplypump, a water suction pump and an air suction pump. These channels aresubjected to contact with living tissues and liquids. However, in orderto clean these channels of the endoscope completely, a relatively longperiod of time is required. Thus, the endoscope can not be utilizedefficiently during the long cleaning time. In a large hospital orclinic, a large number of endoscopes may be prepared in order tomitigate the problem of cleaning time. However, this solution results inan increase in operating costs. Further, in small clinics, it ispractically impossible to prepare a number of expensive endoscopes.

Moreover, the endoscope might be broken during cleaning, and the usablelife of the endoscope is liable to be shortened by the cleaning.

In order to avoid the above-explained various problems, there has beenproposed an endoscope system, in which the endoscope is covered with adisposable protection sheath-like cover having channels formed therein.For instance, U.S. Pat. Nos. 4,721,097, 4,741,326, 4,825,850, 4,869,238,4,991,564, 4,991,565 and 5,050,585 disclose various kinds of disposableprotection sheath-like covers having channels formed therein. In U.S.Pat. No. 4,646,722, there is shown an endoscope system in which theendoscope is covered with a protection sheath, while a tube havingchannels formed therein is inserted into a U-shaped cutout formed in anouter surface of the endoscope along a longitudinal axis thereof. Upondiagnosis, the insertion section of the endoscope is covered with theprotection sheath, and after the inspection, the sheath is removed fromthe insertion section and is then discarded. Therefore, it is no longernecessary to clean the endoscope after every inspection.

In the above-mentioned U.S. Patents, the protection sheath-like cover isconstructed to cover only the insertion section of the endoscope, butdoes not cover an operation section of the endoscope. It should be notedthat the operation section of the endoscope is handled by doctors andoperators and thus is brought into contact with the living tissues andliquids of a patient. Therefore, in order to remove the contamination ofthe operation section of the endoscope due to such living tissues andliquids, it is advantageous to cover not only the insertion section, butalso the operation section of the endoscope. In European PatentPublication No. 0 349 479 A1, there is disclosed an endoscope system, inwhich not only the insertion section, but also the operation section, ofthe endoscope are covered with a disposable protection cover. That is tosay, the protection cover comprises a sheath-like portion for coveringthe insertion section of the endoscope and a bag-like portion forcovering the operation section, the sheath-like portion and bag-likeportion being integrally formed. It has been also proposed to form thesheath-like portion and bag-like portion as separate covers. Forinstance, in European Patent Publication No. 0 341 719 A1, there isproposed another known endoscope system, in which an insertion sectionof an endoscope is covered with a sheath-like disposable protectioncover and an operation section of the endoscope is covered with abag-like disposable protection cover which is mated or joined with thesheath-like cover in order to prevent contamination through the junctionof the sheath-like cover and the bag-like cover.

In the known endoscope system including the insertion section coverhaving an insertion section inserting channel and a forceps channel, theconstruction of the forceps channel, e.g. length, inner diameter,strength, material, configuration and shape, is not formed such thatvarious forceps, i.e. treating tools for ordinary without-cover(coverless) endoscopes, which are not used together with the disposableprotection covers, can be commonly used for the endoscope system. Thatis to say, specially prepared forceps are provided for use in theendoscope system. As is apparent, this is very inconvenient and is noteconomical. Further, if a forceps for a coverless endoscope iserroneously used for the endoscope system including the endoscope anddisposable protection cover, either or both of the forceps and theprotection cover might be broken.

Further, in the known endoscope system, various kinds of forceps areprepared and a desired forceps is used. In the present specification,two forceps for performing the same treatment, but having differentouter diameters, are considered to belong to different kinds of forceps.It should be noted that the outer diameter means a maximum diameter of aforceps and generally a diameter of a distal end treating portion. Asstated above, there have been proposed various kinds of forceps for usein the ordinary coverless endoscopes, and these forceps can beclassified into several groups in accordance with the outer diameter.Similarly, various kinds of forceps for use with disposable protectioncovers of the above-mentioned endoscope system can be classified intoseveral groups in accordance with the outer diameters. However, theforceps groups for the disposable protection covers are not mated withthe forceps groups for the coverless endoscopes. This means that theforceps for the coverless endoscopes can not be commonly used for thedisposable protection covers, and thus sometimes suitable treatments cannot performed. Moreover, an operator can not utilize the familiarforceps for the coverless endoscopes, so that the operator might besubjected to mental stress.

For coverless endoscopes, there have been prepared a very large numberof different kinds of forceps, and thus the number of groups of forcepsis quite large. However, in the endoscope system including thedisposable protection cover with a forceps channel and the endoscopewithout a forceps channel, it is desired to discard the forceps togetherwith the cover. Therefore, it is desired to prepare forceps which areclassified into a smaller number of groups.

In the above-mentioned endoscope system including the endoscope anddisposable protection cover with forceps channel, a position of theforceps channel in a cross-section, at the distal end of the insertionsection cover, is not identical with a position of the forceps channelin a cross-section at a connecting portion between the insertion sectioncover and the operation section cover. In other words, the forcepschannel is twisted within the insertion section cover. Thus, the forcepscan not be smoothly inserted into the forceps channel, and a relativelylarge force is required for inserting the forceps. Furthermore, duringthe insertion of the forceps, a tip of the forceps might be hit on aninner wall of the forceps channel and might be broken or the inner walldamaged. The above-mentioned drawback is manifest when a length of theforceps is long. When the forceps channel is twisted, the forcepschannel is clogged upon bending the protection cover, and therefore theforceps could not be inserted any more.

In the known disposable protection cover, the operation section coverfor covering the operation section of the endoscope is made of softmaterial, because the operating members provided on the operationsection have to be operated on the protection cover. That is to say, ifthe operation section cover is made of rigid or semi-rigid material, theoperating members could not be operated positively. Therefore, theoperation section cover might move relative to the operation section ofthe endoscope. This results in that the operator can not grasp theoperation section firmly, and therefore the operator can not handle theoperation section effectively and might be subject to fatigue.

SUMMARY OF THE INVENTION

The present invention has for its object to provide a novel and usefulendoscope system in which the forceps for use in coverless endoscopescan be commonly utilized for the endoscope system having the disposableprotection cover with forceps channel, so that the above-explainederroneous selection of the forceps can be positively prevented and theexamination procedure can be performed easily and reliably.

It is another object of the invention to provide a novel and usefulendoscope system, in which various kinds of forceps can be efficientlyutilized.

It is another object of the invention to provide a novel and usefuldisposable protection cover with a forceps channel, in which the forcepscan be smoothly inserted into the forceps channel without damaging theforceps or an inner wall of the forceps channel.

It is still another object of the invention to provide a novel anduseful disposable protection cover, in which the operation section ofthe endoscope covered with the protection cover can be firmly grasped,so that the operator can handle the operation section easily andpositively without feeling fatigued.

According to a first aspect of the present invention, an endoscopesystem includes an insertion section insertable into a cavity underinspection and an operation section to which a proximal end of theinsertion section is connected and a disposable protection cover forcovering at least the insertion section of the endoscope and having aforceps channel extended within the protection cover, wherein theforceps channel of the disposable protection covers is constructed suchthat forceps for use in normal coverless endoscopes can be used for thedisposable protection cover.

According to the invention, a length and an inner diameter of theforceps channel of the disposable protection cover are set on the basisof the forceps to be used such that several types of protection covershaving different lengths and inner diameters of forceps channels areprepared in accordance with organs to be treated and treatment methods.Further, the configuration and shape of the forceps channel aredetermined such that forceps for a normal coverless endoscope can beinserted into the forceps channel. In this case, forceps having a movingmechanism at a distal end, such as grasping forceps, can be inserted andremoved into and from the forceps channel. Further, when the insertionsection is bent by a maximum angle, the forceps can be inserted andremoved into and from the forceps channel. In this connection, it shouldbe noted that the inner diameter of the forceps channel should not bemade larger unnecessarily, because then a diameter of the disposableprotection cover also becomes larger.

Moreover, according to the invention, contaminated liquids should notflow out of the forceps inlet opening during the examination or duringthe sucking operation and should not be spread when the forceps isremoved from the forceps channel. Further, the forceps may be of adisposable type or of a reusable type.

According to a second aspect of the invention, an endoscope systemincludes at least one endoscope having an insertion section insertableinto a cavity under inspection and an operation section to which aproximal end of the insertion section is connected, a plurality ofdisposable protection covers, each having an insertion section cover forcovering an insertion section of an endoscope and a forceps channelextending within the insertion section cover, inner diameters of theforceps channels being different from each other, and a plurality offorceps having different outer diameters, wherein each of the innerdiameters of the forceps channels of the plurality of disposableprotection covers is set to be larger, by a predetermined amount, thanthe substantially same outer diameter of a plurality of forceps, thenumber of which is maximized in an outer diameter series.

In a preferable embodiment of the endoscope system according to theinvention, there are prepared three kinds of disposable protectioncovers with forceps channels having inner diameters of 2.0 mm, 2.8 mmand 3.7 mm. Then, for the protection cover having a forceps channel of2.0 mm, a plurality of forceps having outer diameters smaller than 1.8mm can be utilized, for the protection cover having a forceps channel of2.8 mm, a plurality of forceps having outer diameters smaller than 2.4mm can be used, and for the protection cover with the forceps channelhaving a diameter of 3.7 mm, a plurality of forceps having outerdiameters smaller than 3.1 mm can be utilized. According to theinvention, the predetermined amount should be determined such that theforceps can be easily inserted into the forceps channel, the forceps canbe operated effectively, and liquids can be effectively sucked throughthe forceps channel even if the forceps is inserted therein.

According to a third aspect of the invention, a disposable protectioncover is provided for use in an endoscope system including an endoscopehaving an insertion section insertable into a cavity under inspectionand an operation section to which a proximal end of the insertionsection is connected and a disposable protection cover having aninsertion section cover for covering the insertion section of theendoscope, an operation section cover for covering the operation sectionof the endoscope and a forceps channel extending from a proximal end toa distal end of the insertion section cover. A center coordinate of theforceps channel in a cross-section perpendicular to a longitudinal axisof the insertion section cover at the distal end of the insertionsection cover is substantially identical with a center coordinate of theforceps channel in a cross-section perpendicular to the longitudinalaxis at a connecting portion between the insertion section cover and theoperation section cover.

In such a disposable protection cover according to the invention, theforceps channel extends straight within the insertion section cover, andthus the forceps can be easily inserted into the forceps channel withoutcausing any trouble.

According to a fourth aspect of the invention, a disposable protectioncover is provided for use in an endoscope system including an endoscopehaving an insertion section insertable into a cavity under inspectionand an operation section to which a proximal end of the insertionsection is connected and a disposable protection cover having aninsertion section cover for covering the insertion section of theendoscope and an operation section cover for covering the operationsection of the endoscope. The operation section cover comprises a firstcover portion, for covering a grip portion of the operation section,made of rigid or semi-rigid material and a second cover portion, forcovering the remaining portion of the operation section of theendoscope, made of soft material.

In such a disposable protection cover according to the invention, thegrip portion of the operation section of the endoscope is covered withthe first cover portion made of rigid or semi-rigid material, so thatthe operator can grasp the grip portion firmly, and further theremaining portion of the operation section is covered with the secondcover portion made of soft material, so that the operation memberprovided on the operation section can be operated over the second coverportion without difficulty.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the whole construction of anembodiment of the endoscope system according to the invention;

FIG. 2 is a front view illustrating the construction of the operationsection of the endoscope shown in FIG. 1;

FIG. 3 is a perspective view depicting the distal end of the insertionsection of the endoscope;

FIG. 4 is a perspective view illustrating the construction of the distalend of the insertion section cover;

FIG. 5 is a longitudinal cross sectional view showing the endoscopesystem shown in FIG. 1;

FIG. 6 is a cross sectional view depicting the insertion section of theendoscope system according to the invention;

FIG. 7 is a cross sectional view showing the connecting portion of theendoscope system shown in FIG. 7;

FIGS. 8A, 8B, 8C and 8D are schematic views illustrating the overallconstruction of the endoscope system according to the invention;

FIGS. 9 and 10 are schematic side views showing another embodiment ofthe endoscope system according to the invention;

FIG. 11 is a perspective view illustrating the end portion of theuniversal cord of the embodiment shown in FIGS. 9 and 10;

FIGS. 12A and 12B are cross-sectional views showing another embodimentof the protection cover according to the invention;

FIG. 13 is a cross-sectional view illustrating another embodiment of theinsertion section cover according to the invention;

FIG. 14 is a schematic view depicting various forceps for use in theendoscope;

FIG. 15 is a graph showing the relation between the outer diameter ofthe forceps and the number of the forceps;

FIGS. 16 and 17 are schematic views illustrating two embodiments of theendoscope system according to the invention;

FIGS. 18A and 18B depict another embodiment of the endoscope systemaccording to the invention;

FIGS. 19A and 19B show another embodiment of the endoscope systemaccording to the invention;

FIGS. 20A and 20B illustrate another embodiment of the endoscope systemaccording to the invention;

FIG. 21 is a schematic view showing another embodiment of the protectioncover according to the invention;

FIG. 22 is a side view representing the endoscope system using the covershown in FIG. 21;

FIG. 23 is a perspective view illustrating an embodiment of the gripcover according to the invention;

FIG. 24 is a perspective view showing another embodiment of the gripcover;

FIG. 25 is a schematic side view showing another embodiment of theendoscope system according to the invention;

FIG. 26 is a perspective view illustrating the video camera cap shown inFIG. 25;

FIGS. 27A and 27B depict another embodiment of the endoscope systemaccording to the invention;

FIGS. 28A and 28B show an embodiment of the apparatus for inserting theendoscope into the protection cover according to the invention;

FIGS. 29A and 29B represent still another embodiment of the apparatusaccording to the invention;

FIG. 30 is a cross-sectional view illustrating another embodiment of theprotection cover according to the invention;

FIG. 31 is a front view showing the insertion section of the protectioncover shown in FIG. 30;

FIGS. 32 and 33 are cross-sectional views cut along lines 32--32 and33--33 in FIG. 31, respectively;

FIGS. 34A and 34B are cross-sectional views showing the manner ofsecuring the window; and

FIGS. 35A, 35B, 35C and 35D are cross-sectional views illustratingseveral embodiments of the insertion section cover according to theinvention.

EXPLANATION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a schematic view showing an embodiment of the endoscope systemaccording to the invention including an endoscope apparatus anddisposable protection cover. The endoscope apparatus comprises anendoscope 13 having an insertion section 11 and an operation section 12with which a proximal end of the insertion section is coupled, and anexternal apparatus 14 coupled with the endoscope 13. The externalapparatus 14 comprises a video processor 15 having a circuit for drivinga solid state image sensor, provided within a distal end of theinsertion section 11, and a circuit for processing an image signal readout of the solid state image sensor, a monitor device 16 for displayingan image of an object under inspection by processing the image signalsupplied from the video processor 15, a light source device 17 foremitting light for illuminating the inside of a cavity by means of alight guide optical fiber bundle extending within the insertion section11, a fluid control device 18 for supplying air and water and suckingliquids, and an inflator 19 for inflating the disposable protectioncover in order to inflate the disposable protection cover such that theinsertion section 11 of the endoscope 13 can be easily inserted into andremoved from the disposable protection cover as will be explained laterin detail. These devices are installed in a box 20 having casters. Thevideo processor 15 and light source device 17 are coupled with theoperation section 12 of the endoscope 13 by means of signal conductorsand a light guide optical fiber bundle provided in a universal cord 21,and the fluid control device 18 is coupled with conduit channelsprovided within the disposable protection cover by means of conduittubes arranged along the universal cord 21. The construction andoperation of the above-mentioned devices, except for the inflator 19,are well known in the art, so that detailed explanation thereof isdispensed with.

The disposable protection cover of the present embodiment comprises aninsertion section cover 22 for covering the insertion section 11 of theendoscope 131, an operation section cover 23 for covering the operationsection 12 of the endoscope and a universal cord cover 24 for coveringthe universal cord 21. These disposable protection covers 22, 23 and 24are formed separately from each other, and suitable coupling mechanismsare provided between junctions thereof in order to avoid possiblecontamination through the junctions.

The protection covers 22, 23 and 24 may be made of various materials.For instance, flexible vinyl and rubber may be used as a soft materialand rigid or semi-rigid plastics may be used as a hard material. Itshould be noted that the protection covers 22, 23 and 24 are not alwaysnecessarily made of the same material, but may be made of differentmaterials. For instance, the insertion section cover 22 may be made offlexible rubber, the operation section cover 23 may be made of rigidplastics and the universal cord cover 24 may be made of semi-rigidvinyl.

Prior to the actual examination, a set of protection covers is removedfrom a package and a connecting portion 25 made of rigid or semi-rigidplastics and provided at a proximal end of the insertion section cover22 is hung from a cover supporting member 27 of a cover supportingdevice 26. In order to prevent the connecting portion 25 of theinsertion section cover 22 from being contaminated, the cover supportingmember 27 may be covered with a disposable cover. As will be explainedlater, the connecting portion 25 of the insertion section cover 22 isutilized to couple the insertion section cover with the operationsection cover 23.

The height of the cover supporting member 27 has to be adjusted suchthat when the insertion section cover 22 is hung from the coversupporting member 27, the distal end of the disposable insertion sectioncover is not brought into contact with the floor. However, if the heightof the cover supporting member 27 is made too high, the insertingoperation becomes difficult, so that the cover supporting member shouldnot be made so high. In such a case, the insertion section cover 22 hasto be supported by an operator.

After the insertion section cover 22 has been hung from the coversupporting member 27, an end of an air supply tube 28 connected to theinflator 19 is coupled with a nipple portion 29 provided in theconnecting portion 25 of the insertion section cover 22, and then theinflator 19 is driven to supply air through the tube 28 into insertionsection cover 22. In this manner, the insertion section cover 22 isinflated, so that the insertion section 11 of the endoscope 13 can beeasily inserted into the insertion section cover 22. Then, the inflator19 is de-energized and the tube 28 is decoupled from the nipple portion29. This inflating operation is also performed upon removing theinsertion section 11 from the insertion section cover 22. After theexamination, the protection covers 22, 23 and 24 are discarded asmedical wastes and the endoscope is cleaned and sterilized after allexaminations for one day have been finished.

FIG. 2 shows the construction of the operation section 12 of theendoscope. To the operation section 12 are connected the insertionsection 11 and universal cord 21. The operation section 12 comprises agrip portion 31 and a main portion 32. The main portion 32 comprisesangle knobs 33 for bending the distal end of the insertion section 11,air and water supply control switch 34, suction control switch 35 andfunction switch 36 for controlling the operation of a camera takingphotographs of the object under inspection. In the present embodiment,the angle knobs 33 are detachably secured to the main portion 32 of theoperation section 12. The angle knobs 33 may be of a disposable typewhich are contained in a package in which the disposable protectioncover is installed or may be reusable after sterilization. To theuniversal cord 21 is connected a connector 21a for connecting a lightguide optical fiber bundle 39, conduit tubes and signal conductors tothe external apparatus 14.

FIG. 3 is a perspective view illustrating the construction of theinsertion section 11 of the endoscope. In the present embodiment, alateral cross-section of a distal end construction member 37 issemicircular and in a front surface 38 of the member 37 there arearranged outlets of a pair of illuminating optical systems, i.e. opticalfiber bundles 39 and an observing optical system 40 provided between theilluminating optical systems.

FIG. 4 is a perspective view depicting the construction of a distal endof the insertion section cover 22 and FIG. 5 is a longitudinalcross-sectional view showing the insertion section cover 22 into whichthe insertion section 12 of the endoscope is inserted. In a frontsurface of a distal end construction member 41 of the insertion sectioncover 22, there are provided a semicircular observation window 42 madeof transparent material, a nozzle 43 for ejecting air and water towardthe window 42, and an outlet opening 44 of a forceps channel 52. Byejecting the air and water from the nozzle 43, the outer surface of theobservation window 42 can be cleaned.

To the distal end construction member 41 of the insertion section cover22 is connected one end of an insertion section cover tube 45 whichisolates a main portion of the insertion section 12 from the outside.This cover tube 45 is made of a flexible material. The other end of thecover tube 45 is connected to the connecting portion 25 of the insertionsection cover 22.

As illustrated in FIG. 5, within the distal end construction member 37of the insertion section 11 which faces with the observation window 42of the distal end construction member 41 of the insertion section cover22, there are arranged an observing lens system 46 for forming an imageof an object under inspection and a solid state image sensor 47 forpicking-up the image of an object under inspection. The solid stateimage sensor 47 is electrically connected to the video processor 15(FIG. 1) by means of signal conductors 48 extending through theinsertion section 11 and universal cord 21.

Within the insertion section cover 22, there is formed an endoscopeinsertion channel 49 into which the insertion section 11 is inserted,air supply conduit channel 50 which communicates with the air and waterejecting nozzle 43, water supply conduit channel 51 which alsocommunicates with the nozzle 43, and forceps channel 52. These channelsare arranged in parallel with each other. The forceps channel 52 iscommunicated with a forceps inlet opening 53 provided in the connectingportion 25 and is also communicated with the fluid control device 18 bymeans of a conduit tube provided within the universal cord 21.Therefore, the forceps channel 52 is sometimes called a suction channel.Further, the conduit channels 50, 51 and forceps channel 52 are alsocalled conduit tubes in the present specification.

In order to bend the distal end of the insertion section 11 by operatingthe angle knobs 33 such that an optical axis of the observing opticalsystem 46 is moved up and down as well as right and left, there isprovided a bending portion 54 adjacent to the distal end constructionmember 37 of the insertion section 11 of the endoscope. The bendingportion 54 comprises a series of nodal rings 55 which are coupled witheach other by means of journal pins 56, a front end ring of which isconnected to the distal end construction member 37 of the insertionsection 11. A pair of wires 57 are secured to the front end ring 55 atdiametrically opposing points. These wires 57 are extended within theinsertion section 11 and are wound around a pair of pulleys provided inthe operation section 12. The series of nodal rings 55 are covered witha flexible rubber tube 59 in a liquid tight manner. By operating theangle knobs 33, the pulleys may be rotated and thus the wires 57, 58 maybe moved so as to direct the distal end of the insertion section 11 in adesired direction. This construction is well known in the art, so thatits detailed explanation may be dispensed with. At a proximal end of theconnecting portion 25, there are formed a ring-shaped recess 25a forconnecting the operation section cover 23 and a ring shaped recesses 25bfor engaging the connecting portion with the supporting member 27 on thesupporting stand 26.

As illustrated in FIG. 5, in the outer surface of the connecting portion25, there are formed flange 25a and ring shaped recesses 25b and 25c.The operation section cover 23 comprises a first portion 23a made ofsemi-rigid material and a second portion 23b formed by a flexible tube.An end of the first portion 23a is secured to the flange 25a of theconnecting portion 25 while one end of the second portion 23b is clampedbetween the flange 25a and the first portion 23a. The other end of thesecond portion 23b is secured to the ring-shaped recess 25c by means ofa rubber band 23c. The ring-shaped recess 25b serves to support theinsertion section cover 22 onto the supporting member 27 when theinsertion section 11 of the endoscope is inserted or removed into orfrom the insertion section cover 22.

According to the first aspect of the present invention, the forcepschannel 52 is constructed such that a plurality of forceps for use inordinary coverless endoscopes can be commonly utilized. That is to say,the length, inner diameter, strength, material, configuration and shapeof the forceps channel of the protection cover are determined such thatvarious types of forceps which have been proposed for coverlessendoscopes can be utilized.

FIGS. 6 and 7 show another embodiment of the disposable protection coverfor use in the endoscope system according to the present invention. Thisdisposable protection cover is used for an upper endoscope forinspecting and treating the oesophagus, stomach and duodenum. FIG. 6 isa cross-sectional view showing distal end portion 101 and bendingportion 102 of an insertion section cover 105 under such a conditionthat the bending portion is bent at a maximum bending angle so that aradius of curvature R of a longitudinal center axis of a forceps channeltube 103 is at a minimum. In FIGS. 6 and 7, an insertion section 111 ofan endoscope inserted into an insertion section inserting channel 104 isshown schematically.

The insertion section cover 105 of the disposable protection covercomprises an outer cover tube 106 and a distal end construction member107 made of a rigid material. In the distal end construction member 107,an observation window 108 and a forceps outlet opening 109 are formed. Adistal end 112 of the insertion section 111 of the endoscope is broughtinto contact with an inner wall of the observation window 108. Theinsertion section 111 of the endoscope comprises a bending portion 113.In FIG. 6, the bending portion 113 is bent in an upward direction by amaximum bending angle and to the right by a maximum bending angle. Itshould be noted that the bending portion 102 and outer cover tube 106 ofthe insertion section cover 101 are formed such that the bending portioncan be bent in accordance with bending movement of the insertion section111 of the endoscope. In the present embodiment, the maximum upwardbending angle of the bending portion 102 of the cover is 210° and themaximum rightward bending angle is 100°, thus a radius of curvature ofan inner side of the bending portion 102 is 6 mm.

The distal end construction member 107 has a diameter of 10 mm and hasformed therein air and water supply openings. The outer cover tube 106also has a diameter of 10 mm and is made of resilient synthetic resinhaving a low sliding friction. The outer cover tube 106 is connectedwith the distal end construction member 107 in a liquid tight manner.The outer cover tube 106 has a higher flexibility at the bending portion102 thereof than the remaining portion and has formed therein conduitsfor inserting the forceps channel tube 103 and the insertion section 111of the endoscope. The diameter of the forceps channel tube insertingconduit formed within the insertion section cover 105 is slightly largerthan the diameter of the forceps channel tube 103. The forceps channeltube 103 is inserted freely into the forceps channel conduit except forboth ends thereof.

The forceps channel tube 103 is fabricated using a PTFE tube with a lowsliding friction and has an inner diameter of 2.0 mm. A steel wire iswound around the forceps channel tube 103 and a steel wire is wound atthe bending portion 102, so that the forceps channel tube is hardlypinched at the bending portion 102 upon bending. The forceps channeltube 103 is communicated with a suction conduit 129 formed in aconnecting portion 120, and the suction conduit is connected to asuction device by means of a suction tube 124. In this manner, liquidscan be drawn from the distal end of the insertion section cover 105together with air by means of the forceps channel tube 103. Therefore,the forceps channel tube 103 is sometimes called the suction conduittube.

In the distal end portion 112 of the insertion section 111 of theendoscope, there are provided an observation lens system, a solid stateimage sensor and an outlet of the light guide optical fiber bundle. Thebending portion 113 of the insertion section 111 of the endoscope has alength of about 100 mm and comprises a series of nodal rings each havinga length of 3 to 4 mm. By operating angle knobs provided on theoperation section 131 of the endoscope, the bending portion 113 can bebent up and down as well as to the right and left.

The bending portion 113 of the insertion section 111 of the endoscopehas an outer tube formed by a synthetic resin tube, such as a siliconrubber tube having a thickness of 0.5 mm. The insertion section 111 ofthe endoscope comprises a so-called flex formed by a helically woundsteel wire tube and a so-called braid formed by winding a fine wire onthe flex in a mesh. Around the steel wire tube is provided a syntheticresin tube, such as a urethane tube, having a low slipping friction. Theinsertion section 111 of the endoscope has an oval cross-section andassumes substantially half of a cross-sectional area of the insertionsection cover 101.

As illustrated in FIG. 7, in the connecting portion 120 there is formeda forceps inlet channel 128 having a forceps inlet opening 122. Theforceps inlet opening 122 is closed by a forceps plug 121 made ofresilient material and having a central slit 121a and a central hole121b. The forceps inlet channel 128 is communicated with the suctionconduit 129 as well as a forceps guide channel 130 which is communicatedwith the forceps channel tube 103. A diameter of the forceps channel 128is slightly larger than the diameter of the forceps channel tube 103 orthe diameter of the forceps guide conduit 130 and is inclined withrespect to a longitudinal axis of the insertion section cover 105 by anangle of 30° to 45°. The diameter of the suction conduit 129 issubstantially equal to the diameter of the forceps channel tube 103.

A distal end of the operation section 131 of the endoscope is taperedand is detachably inserted into an operation section inserting opening132 formed in the connecting portion 120 of the protection cover. At ajunction between the insertion section 111 and the operation section 131of the endoscope, there is formed a step so that a space is formedbetween the endoscope and the connecting portion 120 of the protectioncover, and this space is communicated with the insertion section channel104. In the connecting portion 120 there is provided a nipple portion134 which is communicated with the inflator (not shown in FIG. 7) bymeans of the inflating tube 133.

The connecting portion 120 is made of molded synthetic resin having alow sliding friction such as general-purpose engineering plastics, sothat a forceps 147 made of steel or synthetic resin can be smoothlyinserted into the forceps inlet channel 128 and forceps guide conduit130. The proximal end of the forceps channel tube 103 is secured in aliquid tight manner to the forceps guide conduit 130 over a length ofabout 10 mm by means of an epoxy cementing agent. The outer surface ofthe forceps channel tube 103 is chemically treated in order to increasethe adhesive force. The proximal end of the outer cover tube 106 isfused to the end face of the connecting portion 120 in a water prooffashion as well. A 100 mm portion of the outer cover tube 106 extendingfrom the fused end is formed rather rigidly in order to increase theresiliency of the outer cover tube. Therefore, the outer cover tube 106is hardly bent at the junction between the connecting portion 120 andthe distal end of the outer cover tube.

FIGS. 8A to 8D are schematic views showing the relationship between thedisposable protection covers 114 and the forceps 147 which are developedfor ordinary coverless endoscopes. The length L1 of the forceps channeldefined by the forceps channel tube 103, forceps guide conduit 130 andforceps inlet channel 128 is determined to be shorter than the length L2of an insertion portion of the forceps 147, i.e. a sum of a length (50mm) of a distal end portion of the forceps which protrudes from thedistal end construction member 107 and a length (150 to 350 mm) of aproximal end portion of the forceps, which is required for operating theforceps, is approximately 200 to 400 mm. The inner diameter of theforceps channel is larger than a maximum outer diameter of a mostfrequently used forceps by about 0.2 to 0.4 mm. It should be noted thatforceps having outer diameters smaller than said maximum outer diametermay be used. The forceps channel should be constructed with asufficiently large inner diameter and should be made of material havingsufficiently large mechanical strength and sufficiently low slidingfriction, so that the forceps can be smoothly inserted into the forcepschannel using a relatively small force not larger than 1.5 Kg although alength of the distal end construction member 107 of the protection coveris long and the bending portion 102 is bent to the maximum bending angleas shown in FIG. 6.

For instance, the length of the central slit 121a and the length of thediameter of the central hole 121b formed in the forceps plug 121 arelarger than the length of the outer diameter of the most frequently usedforceps by 1 mm and 0.3 mm, respectively. When this is the case, theforceps can be inserted into the forceps channel without difficulty andthe leakage of liquids can be prevented effectively through the use ofsuction. The slit 121a serves to wipe liquids off the forceps when theforceps is drawn from the forceps channel. When a forceps having alarger diameter is necessary, the forceps plug 121 is removed from theforceps inlet opening 122. To allow repeated removal and insertion, theforceps plug 121 is preferably made of silicon rubber having a tearingstrength of 45 Kgf/cm² under a JIS A-type tear test.

In order to insert and remove the forceps into and out of the forcepschannel smoothly, it is preferable that the forceps channel has no sharpsteps or bent portions. The inner diameter of the forceps channel islarger than the maximum diameter of the forceps by 0.5 mm and theforceps inlet channel 128 is inclined with respect to the longitudinalaxis of the insertion section cover 105 by 32° and the forceps guideconduit 130 is inclined with respect to the longitudinal axis by 10°.

The forceps channel tube 103 is made of a material which hassufficiently high mechanical strength, low sliding friction, largeresiliency and is difficult to deform. In the present embodiment, theforceps channel tube 103 is made of non-packed PTFE and has a thicknessof 0.5 mm. At the bending portion 102, semicircular recesses having adepth of 0.2 mm are formed in the outer surface at a pitch of 0.5 mmhelically. A steel wire having a diameter of 0.2 mm is wound around thebending portion 102 and is fixed to the bending portion 102 by a thincoating of urethane resin. This construction reinforces the bendingportion 102 making it difficult for the forceps channel formed thereinto become pinched off even when the bending portion 102 is bent to themaximum bending angle such that the radius of curvature R is equal to 7mm.

In the present embodiment, PTFE has a tensile strength of 300 Kgf/cm²under ASTM test 638, an expansion ratio of 300% and a durometer hardnessof D55 under ASTEM test D2240. The distal end construction member 107 ismade of SUS 303 and a portion of the distal end construction member 107on which the distal end of the forceps channel tube 103 is secured has alength shorter than 5 mm. This allows the forceps channel to be bentsmoothly even when the bending portion 102 of the insertion sectioncover 101 is bent at the maximum bending angle. The forceps channel tube103 is firmly secured to the distal end construction member 107 in aliquid tight manner by an epoxy resin adhesive agent. The inner diameterof the forceps outlet opening 109 is the same as the inner diameter ofthe forceps channel tube 103. The inner wall of the forceps outletopening 109 has a polished surface with a roughness less than 6.3 and alength shorter than 10 mm.

By constructing the disposable protection cover mentioned above, aforceps with a rigid distal end shorter than 15 cm can be smoothlyinserted into the forceps channel even under a condition that thebending portion 102 is bent to the maximum bending angle as shown inFIG. 6. It should be noted that the forceps channel tube 103 providedbetween the distal end construction member 107 and the connectingportion 120 has such a length that the distal end of the tube is able tobe deformed and inserted into the forceps outlet opening 109 formed inthe distal end construction member 107 by 2 to 3 mm, so that even if therigid tip of the forceps is brought into contact with the inner wall ofthe forceps channel tube during the inserting operation, the tube is notextended.

In the present embodiment, in order to utilize a plurality of forcepswhich have been developed to be used for normal coverless endoscopes andhave different lengths, outer diameters and shapes, in accordance withorgans to be treated and corresponding treatment, the forceps channelsof the disposable protection covers are formed in the following manner.

                  TABLE 1                                                         ______________________________________                                        Forceps                Forceps Channel                                                              Outer           Inner                                                         diameter        diameter                                Organs  L 2 mm        mm       L 1 mm mm                                      ______________________________________                                        Stomach Biopsy Forceps 1550                                                                         2.6      1030   2.8                                             Grasping Forceps                                                                            3.3      1030   3.7                                             1650                                                                  Duodenum                                                                              Diathernary Wire                                                                            1.8      1300   2.0                                             Cutter 1900                                                                   Diathernary   1.8      1300   2.0                                             Coagulator 1900                                                       Ileum   Grasping Forceps                                                                            3.4      1350   3.7                                             1650                                                                  ______________________________________                                    

When it is desired to use an upper forceps 147 having the length L2 of1550 to 1650 mm and an outer diameter of 2.4 to 2.6 mm as shown in FIG.8A for the oesophagus, stomach and duodenum, a disposable protectioncover comprising the forceps channel having a length L1 of 1330 mm and ainner diameter of 2.8 mm may be employed. Further, when it is desired touse an upper forceps 147 having a length L2 of 1650 mm and an outerdiameter of 3.3 to 3.5 mm as shown in FIG. 8B for the ileum, adisposable protection cover comprising the forceps channel having alength L1 of 1350 mm and an inner diameter of 3.7 mm may be employed.

When it is required to employ forceps having a length L2 of 1550 to 1650mm and an outer diameter of 3.3 mm as illustrated in FIG. 3C for thestomach, a disposable protection cover comprising the forceps channelhaving a length L1 of 1350 mm and an inner diameter of 3.7 mm may beused. Moreover, when it is desired to use forceps having a length L2 of1800 to 2000 mm and an outer diameter of 1.8 mm for the duodenum asshown in FIG. 8D, a disposable protection cover with the forceps channelhaving a length L1 of 1300 mm and an inner diameter of 2.0 mm may beemployed.

In order to distinguish the forceps and disposable protection coverseasily, forceps and covers belonging to the same group may be coloredthe same. Further, the forceps channel may be provided such that whenthe disposable protection cover is bent, the forceps channel becomes aninner side. Moreover, it is not always necessary to form the bendingportion 102 of the disposable protection cover such that the bendingportion is bent circularly, but it may be constructed such that thecurvature of the bending portion is gradually smaller toward the distalend construction member 107 so that the forceps can be easily inserted.Further, the forceps channel tube 103 may be reinforced at a junctionpoint between the connecting portion 120 or may be reinforced byproviding the steel wire over its whole length.

It should be further noted that the endoscope may be of the fiber scopetype or may have a plurality of forceps channels. Moreover, thecombination of the forceps and disposable protection covers is notlimited to the above-explained combination, but may be modified invarious ways. For instance, disposable protection covers may beconstructed to be used together with forceps which have been developedfor urinary organs, respiratory organs, obstetrics and gynecology and soon.

As explained above, according to the present embodiment, the operatorcan employ a number of forceps which have been developed for ordinarycoverless endoscopes also in the endoscope system including thedisposable protection cover. Therefore, it is no longer necessary toprepare a new set of forceps which have been or will be developed to beexclusively used for the endoscope system. Moreover, when the forcepsare used in the endoscope system including the disposable protectioncover, the forceps can be easily prepared and erroneous usage of theforceps can be prevented. Further, the operator can use the usually usedforceps, so that the treatment can be carried out effectively. It shouldbe noted that the coverless endoscope or the with-cover endoscope can beselectively used in accordance with the infection of patients, and thusthe endoscope system can be constructed in an economical and efficientmanner.

FIGS. 9 to 11 show several embodiments of the disposable protectioncover for use in the endoscope system according to the invention. Thedisposable protection cover comprises an insertion section cover havinga connecting portion into which the operation section of the endoscopeis inserted, an outer cover for surrounding the insertion section cover,one end of the outer cover being secured to a distal end of theconnecting portion and the other end having formed therein an openingand the outer cover being made of resilient material, a means forclosing the opening of the outer cover in such a manner that saidopening can be easily opened, and a means for keeping the opened openingof the outer cover such that the endoscope can be easily inserted intothe outer cover through the opening and for fixing the opening to theendoscope.

In FIG. 9, the disposable protection cover 150 comprises an insertionsection cover 105, a connecting portion 120 connected to the insertionsection cover at its proximal end and having a forceps inlet opening 122and an inflating tube nipple portion 134, an air and water supply tubemember 156 and an outer cover 149 which surrounds all theabove-mentioned parts as illustrated in FIG. 9. The outer cover 149 isformed in the shape of a tube having a large diameter and one end of theouter cover is secured to the connecting portion 120 in a liquid tightmanner. The outer cover 149 is made of a transparent synthetic resinsheet having a thickness smaller than 0.5 mm and having good waterproofand expansion properties. For instance, the outer cover 149 may be madeof inexpensive PVC.

At the other end of the outer cover 149, there is provided an openingformed by a band member 155 which is constructed by a resilientsynthetic resin having a thin metal wire embedded therein. The openingis closed by a sealing member 153 made of a synthetic resin sheet suchas a PS sheet having a thickness smaller than 0.2 mm, so that thesealing member 153 can be easily broken. To this end, a cut-in portion154 is formed in the sealing member 153. After exhausting the inside ofthe outer cover 149, the sealing member 153 is fused to the band member155, and then the whole assembly is sterilized by radiation.

Upon using the above-mentioned disposable protection cover 150, thecover is first taken out of a package and an inflating tube 133 isconnected to the nipple portion 134 to inflate the insertion sectioncover 105. Then, the insertion section 111 of the endoscope is insertedinto the insertion section cover 105, and further the operation section131 is inserted into the tapered inlet opening 132 of the connectingportion 120.

Next, the sealing member 153 is broken along the cut-in portion 154 andthen the closed band member 155 is deformed into a substantiallycircular configuration. Then, the band member 155 is moved relative tothe parts 105, 120, 156 surrounded by the outer cover 149 to exposethese parts. At the same time, the operation section 131 and universalcord 151 are covered with the outer cover 149 as shown in FIG. 10. Itshould be noted that the outer cover 149 is preformed such that aportion which surrounds the operation section 131 has a large diameterand a portion covering the universal cord 151 has a small diameter.

After that, the band member 155 is deformed to surround the universalcord 151 such that the tube member 156 is also surrounded by the bandmember as illustrated in FIG. 11. Then, the universal cord 151 iscoupled with the light source device as well as the video processor bymeans of a connector 152, and further the tube member 156 is coupledwith the fluid control device.

After the examination, the band member 155 is manually widened by use ofthe hands and the outer cover 149 is removed to expose the tube member156, universal cord 151 and the operation section 131 of the endoscope.Then, the outer cover 149 is turned over to surround the connectingportion 120, insertion section cover 105 and tube member 156, and theband member 155 is deformed again to close the opening of the outercover 149.

In the disposable protection cover 150 shown in FIGS. 9 to 11, thesterilizing pack and the outer cover 149 are formed integrally as aunitary body, so that the cost can be decreased and further thepreparation can be carried out within a short time. Moreover, thedisposable protection covers of the present embodiment can be stackedone on the other, so that necessary space for storing the covers can bereduced. Furthermore, the opening of the outer cover 149 is formed bythe band member 155 having a metal wire embedded therein, and thus theopening can be easily deformed in a desired shape and the coveringoperation can be performed easily and efficiently. For instance, theband member 155 can be firmly secured to the universal cord 151; theband member is rarely loosened or removed from the universal cord duringthe examination.

Further, after the examination, the contaminated surface of theinsertion section cover 105 is covered with the outer cover 149 suchthat its clean surface faces outward, so that the operator can beeffectively protected from the contamination. Since the one end of theouter cover 149 is secured to the connecting portion 120 in a liquidtight manner, the endoscope is not contaminated. The relative positionof the outer cover 149 and the connecting portion 120 is fixed; theouter cover can be preformed in accordance with the outer configurationof the endoscope.

In the embodiments so far explained, upon inserting the insertionsection of the endoscope into the insertion section cover, the insertionsection inserting channel is inflated. However, when the insertionsection is inserted into the insertion section inserting channel 104,air flows out of the cover from the inlet opening 132. Therefore, theoutput pressure of the inflator has to be increased or a sealing meanshas to be provided on the insertion section of the endoscope. However,when the sealing means is provided, the inserting operation might bedifficult, particularly for a long insertion section. In order toinflate easily the insertion section inserting channel 104, a thicknessof the construction member defining the insertion section insertingchannel 104 may be thin. However, in such a case, the mechanicalstrength becomes weak, and the protection cover might be broken duringthe inserting operation.

FIGS. 12A and 12B show another embodiment of the disposable protectioncover according to the invention, in which the insertion section of theendoscope can be easily inserted into the cover. FIG. 12B is across-sectional view cut along a line 128--128 in FIG. 12A. In thepresent embodiment, the disposable protection cover comprises aninflating conduit channel near the insertion section inserting channelsuch that a thin deformable partition is formed between the insertionsection inserting channel and the inflating conduit channel, aninflating conduit formed in the connecting portion communicates with theinflating conduit channel, and a nipple portion provided in theconnecting portion communicates with the inflating conduit. To thenipple portion an inflating tube is connectable.

In FIGS. 12A and 12B, portions similar to the previous embodiment aredenoted by the same reference numerals, and explanation thereof isdispensed with. In the present embodiment, the insertion section cover105 is constructed to have air and water supply conduits 60 andinsertion section inserting channel 104 integral as a unitary body.Between the insertion section inserting channel 104 and the forcepschannel tube 103 there is formed an inflating conduit channel 158 whichextends along the whole length of the insertion section insertingchannel 104. The inflating conduit channel 158 has a slit-likecross-sectional configuration. A size of the insertion section insertingchannel 104 is made identical with or slightly smaller than that of theinsertion section of the endoscope.

The insertion section cover 105 is formed as a multilumen tube having aplurality of holes formed therein and is secured to the connectingportion 120 in a liquid tight manner. The connecting portion 120 isformed by a mold of synthetic resin such as elastomer which issufficiently resilient and soft and also can be reused. A plurality ofholes and nipple portions are simultaneously formed during the molding.

Between the insertion section inserting channel 104 and the inflatingconduit channel 158 there is formed a partition 159 having a very thinthickness smaller than 0.5 mm, so that the partition is easily deformed.The nipple portion 134 is coupled with an inflator 157 by means of theinflating tube 133. It should be noted that in the present embodiment,the inflator 157 is formed by a suction pump for sucking air within theinflating conduit channel 158 to inflate the insertion section insertingchannel 104. This sucking operation may be carried out by means of asyringe or by the operator. In this case, after the insertion sectionchannel 104 is expanded, the inflating tube 133 is pinched off by meansof a suitable clip. In this manner, the partition 159 is deformed suchthat the insertion section inserting channel 104 is expanded, so thatthe insertion section can be easily inserted into the channel.

After the insertion section of the endoscope has been fully insertedinto the insertion section inserting channel 104, air is introduced intothe inflating conduit channel 158 and the partition 159 recovers itsoriginal shape and the insertion section of the endoscope can be firmlyfixed within the insertion section cover 105. Upon removing theinsertion section of the endoscope from the disposable protection cover,the air is sucked from the inflating conduit channel 158.

In the present embodiment, it is not necessary to form a space betweenthe inner wall of the insertion section inserting channel 104 and theouter surface of the insertion section of the endoscope, and further theinflating conduit channel 158 can be formed in a dead space. Therefore,the diameter of the insertion section cover 105 can be small.Furthermore, the partition 159 can be deformed easily, so that theoutput power of the inflator 157 may be small. Therefore, the inflator157 can be cheap and power can be saved.

Moreover, by sucking the air from the inflating conduit channel 158, thepartition 159 is displaced toward the forceps channel tube 103, so thatthe insertion section inserting channel 104 is expanded. Therefore, theinsertion section of the endoscope can be easily inserted into andremoved from the channel 104, so that it is no longer necessary toprepare a large size cover supporting device. Further, during theexamination, the inflating conduit channel 158 serves as an air cushionfor the forceps channel tube 103 and the necessary force for insertingthe insertion section into the cover can be reduced depending upon thebending angle.

FIG. 13 is a cross-sectional view showing an alternative of theembodiment illustrated in FIGS. 12A and 12B. In the present embodiment,two inflating conduit channels 158 are provided on both sides of theforceps channel tube 103. Therefore, a cross-sectional area of theinsertion section inserting channel 104 is larger than that of theprevious embodiment without reducing a thickness of the partition 159.Upon inserting the insertion section of the endoscope into the insertionsection inserting channel 104, the inflating conduit channels 158 arecommunicated with the atmosphere, and after that, these channels areinflated to fix the insertion section in a desired position. Theconstruction of the present embodiment is particularly advantageous fora protection cover having an insertion section cover with a relativelylarge diameter.

In the embodiment shown in FIG. 13, the operation for inserting andremoving the insertion section of the endoscope can be performed easily,and further during the examination, the channels 158 are inflated, sothat they can give a resiliency. It should be noted that in theembodiments shown in FIGS. 12 and 13, the partition 159 may be providedseparately from the cover tube.

FIG. 14 shows various types forceps for use in upper endoscopes. Itshould be noted that several of the same type of forceps havingdifferent outer diameters are prepared. FIG. 15 is a histogramrepresenting the number of forceps having different outer diameters andthe following Table 2 shows the relationship between the number offorceps and the outer diameters. When the existing forceps areclassified in accordance with the outer diameter, there are severalpeaks in the number of the forceps, as depicted in FIG. 15. In thepresent specification, a forceps whose outer diameter corresponds to apeak is called a standard forceps or most frequently used forceps. InFIG. 15, there are three standard forceps having the outer-diameters of1.8 mm, 2.4 mm and 3.1 mm. According to the invention, there areprepared a plurality of disposable protection covers including forcepschannels having inner diameters which are larger than outer diameters ofthe standard forceps by 1.1 to 1.4 times.

                  TABLE 2                                                         ______________________________________                                        Diameter of                                                                            The        Amount    Inner diameter                                  existing number     of        of forceps                                      forceps (mm)                                                                           forceps    Sales     channel                                         ______________________________________                                        1.0      2          small                                                     1.2      2          small                                                     1.3      3          medium                                                    1.6      1          small                                                     1.7      1          very small                                                1.8      6          large     2.0 (mm)                                        1.9      2          small                                                     2.0      1          very small                                                2.3      2          small                                                     2.4      8          large     2.8 (mm)                                        2.5      1          very small                                                2.6      1          very small                                                3.0      2          small                                                     3.1      10         large     3.7 (mm)                                        3.2      5          small                                                     ______________________________________                                    

According to the present invention, a lower limit of the inner diameterof the forceps channel is determined to be larger than the outerdiameter of the standard forceps by 1.1 times. This is due to the factthat a forceps having a large outer diameter can be used even if theforceps channel is bent or the forceps has a long distal endconstruction member, because the treatment can be performed efficientlyby using the forceps having a large outer diameter. An upper limit ofthe inner diameter of the forceps channel is determined to be largerthan the outer diameter of the standard forceps by 1.4 times. This isdue to the fact that even a forceps having a particularly long distalend construction member can be inserted, the suction through the forcepschannel can be maintained when the forceps is inserted into the forcepschannel, and an outer diameter of the insertion section of theprotection cover should not be made large.

Judging from the histogram shown in FIG. 15 and Table 2, the innerdiameter series of the forceps channels are determined such that themost frequently used forceps can be also utilized in the endoscopesystem including the disposable protection cover. In the presentembodiment, there are prepared three types of disposable protectioncovers with forceps channels having inner diameters of 2.0 mm, 2.8 mmand 3.7 mm for forceps having outer diameters 1.8 mm, 2.4 mm and 3.1 mm,respectively.

FIG. 16 illustrates the whole construction of the endoscope systemaccording to the invention. On a right hand side there are shownprotection covers 114 for videoscopes and on a left side there aredepicted protection covers 114 for fiberscopes. An inner diameter of theforceps channels of disposable protection covers depicted in theuppermost column is 2.0 mm, and thus the forceps 147 having outerdiameters smaller than 1.8 mm can be utilized for these protectioncovers. The disposable protection covers shown in a second column haveforceps channels having inner diameters of also 2.0 mm, but have theforceps channels longer than the above-mentioned covers, so that forcepshaving outer diameters smaller than 1.8 mm and having longer lengths canbe employed for these covers. The protection covers shown in a thirdcolumn have forceps channels having an inner diameter of 2.8 mm, andtherefore the forceps having outer diameters smaller than 2.4 mm can beused. The inner diameter of the forceps channels of the protectioncovers in a fourth column is 3.7 mm, and the forceps havingouter-diameters smaller than 3.1 can be utilized.

The above-mentioned inner diameter series of the forceps channels is anexample, and the inner diameters of the forceps channels may be 2.2 mm,3.2 mm and 4.2 mm for outer diameters of the forceps of 1.8 mm, 2.4 mmand 3.1 mm, respectively by considering the length of the distal endconstruction members of the forceps and the sucking efficiency. Further,the above-mentioned inner diameter series is for the forceps fortreating the stomach, so that for forceps for treating other organs,other inner diameter series may be prepared.

Furthermore, the inner diameter series of the forceps channels of thedisposable protection covers may be determined in accordance with theinner diameter series of the forceps channel of the existing coverlessendoscopes. That is to say, inner diameters of the forceps channels ofthe protection covers may be identical with inner diameters of theforceps channels of a plurality of the most frequently used coverlessendoscopes.

Table 3 represents the inner diameter series of the forceps channels ofthe existing coverless endoscopes. In the endoscope system according tothe invention, an endoscope can be commonly used for a plurality ofdisposable protection covers with forceps channels having differentinner diameters. In the present embodiment, a desired cover may beselected from three kinds of covers including the forceps channelshaving inner diameters of 2.0 mm, 2.8 and 3.7 mm or 2.2 mm, 3.2 mm and4.2 mm. Therefore, it is no longer necessary to prepare forty onedifferent kinds of protection covers with forceps channels having innerdiameters from 1 mm to 5 mm, each being different from one another by0.5 mm, and it is sufficient to prepare the three kinds of protectioncovers with the forceps channels having different inner diameters. InTable 3, the coverless upper endoscopes having forceps channels of 1.5mm, 2.0 mm, 2.8 mm and 3.7 mm are most frequently used, so that in thepresent embodiment there are prepared four different kinds of disposableprotection covers with forceps channels of 1.5 mm, 2.0 mm, 2.8 mm and3.7 mm.

                  TABLE 3                                                         ______________________________________                                        Inner diameter of forceps                                                                       Inner diameter of                                           channel of without-cover                                                                        forceps channel in                                          endoscope (mm)    cover (mm)                                                  ______________________________________                                        1.2                                                                           1.5               1.5                                                         1.7                                                                           2.0               2.0                                                         2.2                                                                           2.6                                                                           2.8               2.8                                                         3.2                                                                           3.7               3.7                                                         4.2                                                                           ______________________________________                                    

FIG. 17 illustrates a whole construction of the endoscope systemaccording to the invention. On a left side there are shown coverlessendoscopes 136 and on a right side there are shown videoscopes withprotection covers. An inner diameter of the forceps channels of thecoverless endoscopes 136 and disposable protection covers 114 depictedin the uppermost column is 1.5 mm and thus the forceps 147 having theouter diameters of 1.0 to 1.3 mm can be utilized. The coverlessendoscopes and disposable protection covers shown in a second columnhave forceps channels having an inner diameter of 2.0 so that theforceps having outer diameters of 1.6 to 1.8 mm can be employed. Thecoverless endoscopes and protection covers shown in a third column haveforceps channels having an inner diameter of 2.8 mm, and thereforeforceps having outer diameters of 1.9 to 2.4 mm can be used. The innerdiameter of the forceps channels of the protection covers in a fourthcolumn is 3.7 mm, and forceps having outer diameters of 2.5 to 3.3 mmcan be utilized.

The above-mentioned example is for the inner diameter series of forcepschannels of the disposable protection cover for the upper endoscope forstomach, and different inner diameter series may be adopted for variousorgans other than the stomach.

FIGS. 18A and 18B show another embodiment of the disposable protectioncover according to the invention. A protection cover 150 of the presentembodiment is similar to the embodiment illustrated in FIGS. 9 to 11,but differs in a point that a grip cover 161 is provided between theconnecting portion 120 and the outer cover 149. The connecting portion120 is made of rigid or semi-rigid synthetic resin, and the outer cover149 is formed by a thin synthetic resin sheet. If the grip portion ofthe operation section 131 of the endoscope is covered with the outercover 149, the outer cover might slip on the grip portion. In thepresent embodiment, the grip cover 161 is made of soft and elasticmaterial such as synthetic rubber and elastomer. Further the grip cover161 is formed to be tightly smaller than the grip portion so that thegrip cover can be tightly fixed on the grip portion.

The grip cover 161 is fused to the connecting portion 120 as well as tothe outer cover 149 in a liquid tight manner and has formed therein acut-out portion 164 so that the movable portions of the operationsection 131, such as the operation buttons 163 and angle knobs (notshown) and a projection 162 at the connection to the universal cord 151,are not covered with the grip cover. At the front end of the outer cover149 there is provided a band member 155 defining the opening.

The disposable protection cover 150 of the present embodiment can beused in entirely the same manner as the embodiment illustrated in FIGS.9 to 11. In this case, the grip portion of the operation section 131 ofthe endoscope is covered with the grip cover 161 made of elasticmaterial, and thus the operator can grasp the grip portion firmly overthe grip cover.

It should be noted that the cut-out portion 164 formed in the grip cover161 may be closed by a very thin film or a plurality of holes formed inthe grip cover through which the operation buttons protrude from thegrip cover. Moreover, anti-slip ridges may be formed on an outer surfaceof the grip cover at portions to be grasped by the operator's fingers.

FIGS. 19A and 19B depict another embodiment of the endoscope systemaccording to the invention. In the present embodiment, the proximal andof the connecting portion 120 is extended to form an extended portion,and the outer cover 149 is secured to an edge of the extended portion.The extended portion of the connecting portion 120 has a thicknesssmaller than that of the remaining portion of the connecting portion120, and a plurality of operation buttons 163 are provided in theextended portion of the connecting portion 120. The configuration of theextended portion of the connecting portion 120 is made substantiallyidentical with the outer configuration of the operation section 131 ofthe endoscope. Also in the present embodiment, the outer cover 149 hasformed therein the cut-out portion 164 so that the angle knobs 168 areexposed. Since the cut-out portion 164 is rather large, the operator caneasily operate the angle knobs 168 without difficulty.

When the operator grips the grip portion of the operation section 131 ofthe endoscope, two electric operation switches (tact switches) 163 fordriving electromagnetic valves which control the air supply, watersupply and suction are operated by an index finger of the operator andtwo electric operation switches (tact switches) 163 for controlling thevideo processor, e.g. freeze switch and release switch, are operated bya thumb of the operator. The operation switches 163 are covered withresilient material, and conductors connected to the switches extendthrough a tube 156 to an electric connector (not shown). Within the tube156 there are also arranged air and water supply tube member 161 andsuction tube 124 to form the universal cord.

As shown in FIG. 19B, the signal conductors 119 connected to the solidstate image sensor, arranged within the distal end of the insertionsection 111, are extended through the operation section 131 as well asthrough the universal cord 151. The universal cord 151 extends from theoperation section 131 at its proximal end. The endoscope can be easilyinserted into the protection cover without being affected by theuniversal cord 151. When the operation section 131 and universal cord151 are covered with the outer cover 149, the operation buttons 163are-exposed, so that the operator can easily and positively operatethese buttons.

FIGS. 20A and 20B show another embodiment of the endoscope systemaccording to the invention. In the present embodiment, a light guideoptical fiber bundle is provided in the disposable protection cover.That is to say, a light guide optical fiber bundle 167 is extendedwithin the insertion section cover 105 in parallel with the insertionsection inserting channel 104 and forceps channel 103. The light guideoptical fiber bundle 167 is passed through the connecting portion 120and is extended out of the connecting portion as the universal cord 151.The air and water supply tube member 160 and suction tube 124 are alsoextended out of the connecting portion 120 together with the light guideoptical fiber bundle 167. The conductors 165 connected to the operationswitches 163 are extended within the extended portion of the connectingportion 120 and are connected to the connector (not shown) by means ofthe universal cord 151. A connector 166a is secured to the proximal endof the extended portion of the connecting portion 120. The opening ofthe outer cover 149 is closed by the chucking means 153.

The signal conductors 119b connected to the solid state image sensor 117provided in the distal end of the insertion section 111 are connected toa socket 166b secured to the operation section 131 of the endoscope.When the endoscope is inserted into the protection cover, the socket166b is electrically and mechanically coupled with the connector 166a.In this manner the solid state image sensor 117 is connected to thevideo processor.

The extended portion of the connecting portion 120 of the cover isformed integrally with the connecting portion by molding. When formingthe connecting portion 120, first a base member having a large thicknessis formed, then various parts are fixed on the base member and finally athin synthetic resin film is coated. In order to couple the parts withthe base member smoothly without producing steps, recesses anddepressions are previously formed in the outer surface of the basemember. It should be noted that the extended portion of the connectingportion 120 has to be formed such that the grip portion can be firmlygrasped and the operation buttons can be positively operated withoutbeing affected by the extended portion.

In the present embodiment, the air and water supply tube member 160,suction tube 124, light guide optical fiber bundle 167, conductors 165and signal conductors 119a all are provided in the universal cord 151,so that the operation of covering the endoscope with the protectioncover and the operation of handling the endoscope during examination canbe performed easily and positively.

In the embodiments shown in FIGS. 18 to 20, the angle knobs may bedetachably secured to the shaft provided on the operation section. Insuch a case, a relatively small aperture may be formed in the extendedportion of the connecting portion, and thus the cut-out portion may besmaller.

According to one aspect of the present invention, the operation sectioncover of the disposable protection cover comprises a grip cover forcovering the grip portion of the operation section and being made ofrigid or semi-rigid material and a top cover for covering the remainingportion of the operation section and being made of soft material, sothat the operator can grasp the grip portion firmly,

FIG. 21 shows such a disposable protection cover according to theinvention. A disposable protection cover 250 of the present embodimentcomprises, in addition to the insertion section inserting channel, aforceps channel and an air and water supply channel. That is to say, theprotection cover 250 comprises a rigid distal end construction member201, flexible insertion section cover 215, connecting portion 220, airand water supply tube member 256, outer cover 249, forceps plug 221,inflating tube 233 and three kinds of grip covers 275 having differentmaterials, sizes and shapes.

The distal end construction member 201, insertion section cover 215 andconnecting portion 220 are coupled with each other in a liquid tightmanner. In the connecting portion 220, forceps inlet opening 226 andnipple portion 234 for connecting the inflating tube and operationsection inserting opening 232 are formed. One end of the outer cover 249is secured to the connecting portion 220 along the periphery of theopening 232 and nipple portion 234. The outer cover 249 is made of atransparent synthetic resin sheet such as PVC having a thickness smallerthan 0.5 mm. The outer cover 249 can be expanded and covers theoperation section 231 of the endoscope and universal cord 251 up to itsconnector as illustrated in FIG. 22. In a shrunken state of the outercover 249, the outer cover surrounds the insertion section cover 215 andconnecting portion 220 as shown in FIG. 21. The outer cover 249 has anopening formed at its other end by a band member 255 which isconstructed by a resilient synthetic resin having a thin metal wireembedded therein. The opening is closed by a sealing member 253 made ofa synthetic resin sheet such as a PS sheet having a thickness smallerthan 0.2 mm, so that the sealing member 253 can be easily broken. Tothis end, a cut-in portion 254 is formed in the sealing member 253.After exhausting (evacuating) the inside of the outer cover 249, thesealing member 253 is fused to the band member 255, and then the wholeassembly is sterilized by radiation. It should be noted that a free endof the tube member 256 is closed by a sealing member.

In the present embodiment, within the outer cover 249, the forceps plug221, inflating tube 233 and three kinds of grip portions 275 arearranged. At first, the sealing member 253 is removed and theabove-mentioned parts are removed from the outer cover. The manner ofusing the disposable protection cover of the present embodiment issimilar to that which has been explained before with reference to theembodiment illustrated in FIGS. 9 to 11, but in the present embodiment,after the operation portion of the endoscope is covered with the outercover 249, the grip portion of the endoscope is further covered with therigid or semi-rigid grip cover 275, so that the operator can grasp thegrip portion of the endoscope firmly. Moreover, the operator can selectthe most suitable grip cover 275 from the three kinds of grip covers.

FIG. 23 shows an embodiment of the grip cover 275. The grip cover 257comprises snap-fits 278 which utilize the resiliency of the syntheticmaterial such as polyethylene, polypropylene, urethane rubber andelastomer, so that the grip cover can be easily and positively coupledwith the proximal end of the connecting portion 220. The grip cover 275further comprises a hinge portion 277 along which a half body of thegrip cover can be bent. The half body of the grip cover 275 is opened asshown by a chain line in FIG. 23, and the base body is secured to theconnecting portion 220 by means of the snap-fit 278. Then, the half bodyis coupled with the base body by means of the snap-fit 278.

FIG. 24 illustrates another embodiment of the grip cover 275 accordingto the invention. The grip cover has a substantially U-shapedcross-section and is coupled with the connecting portion 220 having acorresponding snap-fit 278 by inserting the ridge-like snap-fit 278 ofthe grip cover 275 into the groove-like snap-fit 278 of the connectingportion 220. Further, in the present embodiment, on an outer surface ofthe grip cover 275 there are formed non-slip V-shaped ridges 276. In theembodiment shown in FIG. 23, non-slip projections 276 are formed on thegrip cover 275 such that the projections are aligned in a V-shape on theside walls and are distributed on the front surface. In this manner, theoperator can grasp the grip portion of the endoscope firmly.

FIG. 25 illustrates another embodiment of the endoscope system accordingto the invention. In the present embodiment, use is made of afiberscope, and a video camera 279 is arranged at an eyepiece portion285. A video signal generated by the video camera 279 is supplied via avideo cable 282 to the video processor. The video camera 279 and videocable 282 are also covered with the outer cover 249 together with theuniversal cord 251.

After the video camera 279 is provided on the eyepiece portion 285, theyare surrounded by the outer cover 249. In this case, if the universalcord 251 and video cable 282 have different lengths, the shorter one isextruded from the outer cover 249. When the operation buttons 263 of thevideo camera 280 are covered with the outer cover 249, these buttons cannot be operated easily. In the present embodiment, in order to overcomesuch a disadvantage, a cap 280 shown in FIG. 26 is secured to the headof the video camera 279. The cap 280 is formed to correspond to theouter configuration of the head of the video camera and is made ofrelatively soft transparent material, such as natural rubber, syntheticrubber and elastomer. Thin portions 286 are formed at positionscorresponding to the operation buttons 263 of the video camera 279.Further cut-out portions 281 and 283 are formed in the cap 280 atpositions corresponding to a zooming knob and connector to the videocable 282. The cap 280 is installed within the outer cover 249 togetherwith the grip cover 275.

After the operation section 231 of the endoscope is covered with theouter cover 249, the cap 280 is set on the head of the video camera 279,so that the outer cover is closely applied on the camera head. In thiscase, the operation buttons 263 of the video camera 279 can be easilyoperated by means of the thin portions 286 and the zooming knob can beoperated also easily. It should be noted that the cap 280 may be formedby two separate bodies or two half bodies may be coupled along thehinge.

FIGS. 27A and 27B depict another embodiment of the endoscope systemaccording to the invention. In the present embodiment, the video camera279 and video cable 282 are covered with a second outer cover 249a whichis formed separately from the outer cover 249. In the outer cover 249,there is formed a sealing end 253a at a position corresponding to theeyepiece portion 285 and a rubber band 284 for securing the sealing end253a at the eyepiece portion as illustrated by chain lines.

As shown in FIG. 27B, at one end of the second outer cover 249a, thereis provided a rubber band 284a for securing the cover to the camera headin a liquid tight manner. At the other end of the second outer cover249a there is provided a band member 255a which can be deformed into adesired shape. The second outer cover 249a is installed within the outercover 249, in a folded condition, as shown by chain lines in FIG. 27A.

In the present embodiment, when the video camera 279 is not coupled withthe eyepiece portion 285, the eyepiece portion is covered with the outercover 249 and is secured to the eyepiece portion by means of the rubberband 284 in a liquid tight manner and the image of the object can beobserved by means of the eyepiece in the usual manner. Further, when thevideo camera 279 is coupled with the eyepiece portion 285, the secondouter cover 249a can be secured to the head portion of the eyepieceportion by means of the rubber tube 284a in a liquid tight manner. Inthis case the second outer cover 249a can be easily secured to theeyepiece portion. Further, the band member 255a and rubber band 284a canbe easily deformed into desired shapes, so that various types of videocameras can be utilized.

In the above embodiments, the insertion section cover 205 and outercover 249 are formed integrally as a unitary body, but they may beseparated from each other. Further, the grip cover 275 may be directlyapplied on the grip portion of the operation section of the endoscope.In such a case, the junction between the grip cover and the operationsection cover has to be overlapped or connected with each other suchthat the endoscope is not exposed.

FIGS. 28A and 28B show an embodiment of an apparatus which iseffectively used upon inserting the endoscope 211 into the disposableprotection cover 250. This apparatus comprises first tray 287 forsupporting the cover 250, second tray 288 for holding the endoscope 211and bellows portion 289 for coupling the first and second trays in sucha manner that a distance between these trays can be adjusted. The firstand second trays 287, 288 and 289 are formed in an economical manner byplastic molding which is cheap and reusable. In upper surfaces of thefirst and second trays 287 and 288, inner and outer circular grooves areformed coaxially.

In the inner groove of the first tray 287, the tube member 256 and itsconnector are inserted, and in the outer groove the insertion sectioncover 205 is inserted. The tube members 256 and insertion section cover205 are wound in the counter-clockwise direction. The insertion sectioncover 205 has to be wound loosely to have a large radius of curvature sothat the insertion section of the endoscope can be easily inserted intothe insertion section cover. The connecting portion 220 and asubstantially half portion of the insertion section cover are coveredwith the outer cover 249. The connecting portion 220 is indexed at arecess formed in a top of the outermost ridge in the first tray 287 sothat the connecting portion can be coupled with the inflator by means ofthe inflating tube 233.

The universal cord 251 and its connector are installed in the outergroove of the second tray 288, and insertion section 205 of theendoscope is placed in the inner groove. The universal cord 251 andinsertion section 205 are wound in the clockwise direction. A cut-outportion is formed in the outer groove, and the insertion section 205 isextended therefrom. In a central depression of the second tray 288, theoperation section 231 is inserted such that the angle knobs 268 arefaced downward.

The insertion section 205 of the endoscope is supported by the bellowsportion 289 and there is formed a space between the side wall of thefirst tray 287 and the left side wall of the bellows portion such thatthe index finger and thumb of the operator can be inserted therein. InFIG. 28A, a height of the bellows portion 289 is lower than the uppersurfaces of the trays 287 and 288 so that the insertion section 205 isslightly bent downward. However, when the first and second trays 287 and288 are moved closer to each other, the height of the bellows portion289 is increased, and when these trays are moved away from each other,the height of the bellows portion decreases. Therefore, the distancebetween the first and second trays 287 and 288 is adjusted such that aheight of the bellows portion become substantially equal to a height ofthe trays.

When the insertion section 205 is inserted into the cover, first theinserting section is picked-up by the operator in his/her right hand andthe distal end portion of the insertion section is inserted into theconnecting portion 220 slightly. Then, the insertion section 205 ispicked-up by the operator in his/her left hand and the second tray 288is moved toward the first tray 287 to insert the insertion section intothe cover. It should be noted that the insertion section cover isinflated. Next, the insertion section 205 is pulled out of the secondtray 288 and is placed on the bellows portion 289 while the second trayis moved away from the first tray 287. Then, the above mentionedoperation is repeated. In this manner, the insertion section 205 can beinserted into the insertion section cover 215 in an easy and positivemanner without using a large stand for supporting the insertion sectioncover.

It should be noted that in the above embodiment, the first and secondtrays 287 and 288 are formed integrally with each other, together withthe bellows portion 289. However, the first tray may be formedseparately from the first tray. Then, the first tray may be utilized asa part of the package for the disposable protection cover, and thesecond tray may be used for storing the endoscope.

FIGS. 29A and 29B illustrate another embodiment of the second tray 288of the inserting apparatus according to the invention. In the presentembodiment, in the second tray 288 there is provided rotatably a centertray 290 having the inner groove formed therein, and the operationsection 231 is placed on the center tray such that the shaft to whichthe angle knobs are detachably secured faces upward. The outer groove isinclined outward such that the insertion section 205 is moved outward bythe force of gravity. The universal cord 251 and its connector areinstalled in the inner groove.

In the present embodiment, when the center tray 290 is rotated, theinsertion section 205 is automatically extruded from the outer groove,so that the inserting operation is much easier and further the insertionsection is not picked-up by the operator, and thus it is hardly damaged.It should be noted that the second tray 288 may be arranged to berotated by 90 degrees such that the insertion section 205 is woundaround a horizontal axis. Then, the insertion section may be insertedinto the insertion section cover which is hung by means of a suitablestand.

FIG. 30 is a schematic view showing another embodiment of the presentinvention. In this embodiment, a disposable protection cover 450comprises a distal end portion 401, an insertion section cover 415 and aconnecting portion 420. In the distal end portion 401, a distal endconstruction member 407 is arranged. In a tip portion of the distal endconstruction member 407, a window 408 for observation and lighting, aforceps outlet opening 409 and a washing nozzle 469 for the window 408are arranged as illustrated in FIG. 31 showing a front view from a tipportion side. In a rear portion of the distal end construction member407, an insertion section inserting tube 470 defining an insertionsection inserting channel 404, a forceps channel tube 471 defining aforceps channel 403 and an air and water supply tube 460 defining an airand water channel are respectively connected to the window 408, theforceps outlet opening 409 and washing nozzle 469, as illustrated inFIG. 32, which is a cross-sectional view taken along line 32--32 of FIG.30.

In the insertion section cover 415, an outer cover tube 406 is connectedin a liquid tight manner between the distal end construction member 407of the distal end portion 401 and the connecting portion 420. In theouter cover tube 406, the insertion section inserting tube 470, theforceps channel tube 471 and the air and water supply tube 460 arearranged in an extended manner. The outer cover tube 406 needs goodflexibility characteristics, waterproof properties, slidability, safety,and so on. Therefore, the outer cover tube 406 is formed by, forexample, a tube member such that synthetic resins are coated on a memberstacking a steel flex and a steel braid. Moreover, since the outer covertube 406 needs flexibility, twistability, elasticity and bendability foreasy insertion into an internal organ under a condition such that anendoscope (not shown) is inserted, it is necessary to choose materials,thickness of outer cover tube 406, and a construction of the outer covertube 406 so that the outer cover tube 406 has elasticity at a bendingportion near the distal end portion. It should be noted that the bendingportion of the outer cover tube 406 may be constructed by an anothercover member such as a thin member made of a synthetic rubber tube.

In the connecting portion 420, connector portions of the insertionsection inserting tube 470, the forceps channel tube 471 and the air andwater supply tube 460 are arranged in a tip side thereof, and tubescorresponding to these members are connected to the connector portionsin a liquid tight manner.

In this embodiment, respective tubes 460, 470, 471 and the outer covertube 406 are connected in a straight manner by, for example, inserting ahard rod, and in such a manner that respective tubes are not rotated byusing a mark etc, so that a center axis 0 of the forceps channel tube471 illustrated in FIG. 33, which is a cross-sectional taken along line33--33 of FIG. 30, is identical with a center axis 0 of the forcepschannel tube 471 illustrated in FIG. 32, which is a cross-sectional viewtaken along line 32--32 of FIG. 30, under such a condition that theinsertion section cover 415 is extended naturally. Therefore, if theinsertion section cover 415 is extended naturally, the center axes 0 ofthe forceps channel tube 471 are always identical at arbitrarycross-sections in the insertion section cover 415. In this case,respective tubes 460, 470 and 471 are made of synthetic resins, such asPTFE having good flexibility and slidability characteristics, and have abending strength and a tensile strength sufficient to endure a bendingforce generated when the bending force is applied to the tube 470 havingan endoscope set therein.

Moreover, in the connecting portion 420, a forceps guide conduit 428,having a forceps inlet opening 422 for inserting a forceps 447 andcommunicating with the forceps channel 403, is arranged in an inclinedmanner, and an operation section inlet opening 432 having a cone shapeand communicating with the insertion section inserting channel 404 isalso arranged. In the forceps guide conduit 428, a forceps plugconnecting portion 426 is formed integrally to the forceps inlet opening422, so that a forceps plug 421 can be detachably arranged. Moreover,two branch portions are arranged in the forceps guide conduit 428between the forceps inlet opening 428 and the forceps channel tube. Asuction conduit 429 and a nipple portion 425 are arranged integrallywith the branch portion of the distal end side, and a water supplyconduit 474 and a nipple portion 472 are arranged integrally with thebranch portion of the proximal end side. A proximal end side suctiontube 424 is connected to the nipple portion 425, and a water supply tube473 for supplying a physiological saline solution is connected to thenipple portion 472.

Further, in the connecting portion 420, an inflating conduit 435communicating with the operation section inlet opening 432 and theinsertion section inserting tube 404, and a nipple portion 434 of aninflating tube are integrally arranged. Therefore, in the case of anendoscope inserting operation, it is possible to inflate the insertionsection inserting tube 470 so as to insert easily the endoscope, if aninflating tube (not shown) is connected to the nipple portion 434 andair is supplied.

As mentioned above, according to this embodiment, the center axes 0 ofthe forceps channel tube 471 are identical at arbitrary cross-sectionsin the insertion section cover 415 under a condition such that theinsertion section cover 415 is naturally extended. Therefore, centerpositions of the forceps channel tube 471 do not vary greatly betweencross-sections spaced a distance smaller than a length of the rigiddistal end portion of the forceps 447 in the insertion section cover415, if the forceps channel tube 471 is bent or twisted due to thebending or twisting of the insertion section cover 415 with a largecurvature along for example the esophagus, intestines, etc. or due tothe bending or twisting of the bending portion with a small curvature inthe up and down or right and left directions.

Therefore, if the forceps 447 is inserted from the forceps inlet opening422 through the forceps guide conduit 428 and the forceps channel 403,and a tip portion of the forceps 447 is projected from the forcepsoutlet opening 409 to perform the operation, it is possible to insertthe forceps 447 without making contact with the forceps channel tube471, and thus it is possible to reduce the insertion force. Moreover,since the forceps 471 can be inserted smoothly, it is possible to useforceps 447 having an outer diameter with a relatively large sizesubstantially equal to an inner diameter of the forceps channel 403, andforceps 447 having a long rigid distal end portion can be used.

Moreover, in this embodiment the suction conduit 429 and the nippleportion 425 for the proximal end side suction tube, and the water supplyconduit 474 and the nipple portion 472 are arranged in the forceps guideconduit 428 integrally with the connecting portion. Therefore, if it isnecessary to keep a field of view clear by supplying continuously aphysiological saline solution such as when performing endoscopeobservation in the gall or urinary organs among the internal organs, itis possible to keep the field of view clear by supplying thephysiological saline solution from the nipple portion 472, stopping thesupply of the physiological saline solution and sucking out thephysiological saline solution via the nipple portion 425. Further, it ispossible to wash an inner surface of the organs by supplying a largeamount of the physiological saline solution from the nipple portion 472,and to color an inner surface of the organs by supplying coloringsolutions from the nipple portion 472.

In this manner, since the water supply conduit 474 is arranged in theforceps guide conduit 428 separately from the suction conduit 429, it ispossible to keep the field of view clear by only using the disposableprotection cover 450, and thus it is not necessary to prepare othertubes, such as T-shaped tubes. Moreover, since the water supply conduit474 and the nipple portion 472 are arranged integrally with theconnecting portion 420, the total cost can be reduced. Further, sincethe water supply conduit 474 and the water supply tube 473 can besterilized at the same time with the disposable protection cover 450, itis very convenient to use. After use, since it is possible to disposethe water supply conduit 474 and the water supply tube 473 at the sametime as well as the disposable protection cover 450, it is possible toeliminate washing and sterilizing operations.

In the construction shown in FIG. 30, various methods can be applied forarranging the window 408 for the observation and lighting in the distaland construction member 407. For example, the window 408 may be adheredto the distal end construction member 407 by using adhesive agents,adhesive agents of ultra-violet hardening type, rapidly-drying typeadhesive agents, and so on. Moreover, the distal end construction member407 and the window 408 may be integrally formed by using transparentmaterials, and then portions other than the window 408 may be shieldedby paint. However, in the case of using adhesive agents, it is not easyto automate the assembling operation, and the assembling operation takesa lot of time due to a drying operation of the adhesive agents. In thecase of using the adhesive agents of ultra-violet hardening type, it isdifficult to control an amount of the adhesive agent to be used. In thecase of using the rapidly drying adhesive agents, it is not easy tohandle the adhesive agents, and the window 408 may become opaque.Further, in the case of shielding the portions other than the window408, the total cost of assembly becomes large. Especially, in thedisposable protection cover 450, since it is disposed of after using onetime, it is necessary to manufacture a large number of the disposableprotection covers 450 rapidly and inexpensively, as compared withconventional endoscopes without covers. Therefore, the assemblingoperation is desired to be automated.

In the embodiment mentioned above, the window 408 is fused by using anultrasonic wave and connected to the distal end construction member 407.The ultrasonic wave fusing operation is performed by arranging aprojection 407a, contacting with a whole bottom circular portion of thewindow 408, in the distal end construction member 407 as shown in FIG.34A, or by arranging a step portion 407b, contacting with a whole edgeportion of the window 408, in the distal end construction member 407 asshown in FIG. 34B. In this case, the window 408 is formed by transparentsynthetic resins such as polycarbonate, polystyrene and so on, which aresuitable for the ultrasonic wave fusing operation, and the distal endconstruction member 407 is formed by the same materials as that of thewindow 408 or other materials such as modified polyphenylene oxide,preferably colored black.

In this manner, after the distal end construction member 407 is securedby a supporting member and the window 408 is set in the connectingportion of the distal end construction member 407, an ultrasonic wavehorn is brought into contact with the window 408 so as to transmit anultrasonic oscillation to the window 408. In the embodiment shown inFIG. 34A, the projection 407a is fused by friction heat concentrated onthe projection 407a, and in the embodiment shown in FIG. 34B, the edgeportion of the window 400 is fused by a sheering force. In both cases,the fused portion assumes a liquid tight state. As mentioned above, ifthe window 408 is connected to the distal end construction member 407 byusing ultrasonic wave fusing, the assembling operation becomes easilyautomated, and thus it is possible to manufacture the disposableprotection covers 450 rapidly in a large scale.

The present invention is not limited to the embodiments mentioned above,but various modifications are possible. For example, in the embodimentmentioned above, the air and water supply tube 460 is also arranged atthe same positions at the cross-sections between a portion near thedistal end portion 401 and a portion near the connecting portion 420 andthe insertion section cover 415 as shown in FIGS. 31 and 32, but it ispossible to vary the positions of the portions at the cross-sectionscorresponding to a layout of the distal end construction member 407 or alayout of the connecting portion 420, since only fluid is passingthrough the air and water supply tube 460. Moreover, the insertionsection inserting channel 404 is arranged preferably at the samepositions on the cross-sections mentioned above, but it is possible tovary the positions thereof slightly.

Further, in the embodiment mentioned above, the water supply conduit 474is arranged to the forceps guide conduit 428, but the other water supplyconduit 474 could be further formed along the distal end portion 401,the insertion section 415 and the connecting portion 420 in addition tothe forceps guide conduit 428. Moreover, in the embodiment mentionedabove, the forceps plug 421 is connected to the forceps plug connectingportion 426, but it is possible to use a so-called T-shaped tube insteadof the forceps plug 421. Further, the nipple portion 425 for theproximal end side suction tube and the nipple portion 472 are arrangedat an upper surface of the connecting portion 420, but they can bearranged at a side surface or at a rear portion thereof if it does notdisturb operation of the forceps 447.

Further, in the embodiment mentioned above, the outer cover tube 406,the air and water supply tube 460, the insertion section inserting tube470 and the forceps channel tube 471 are formed respectively bydifferent tube members, but it is possible to form all or a part of themintegrally to construct a multilumen. FIGS. 35A to 35D arecross-sectional views respectively showing the multilumen construction.In FIG. 35A, the insertion section inserting channel 404 and the outercover tube 406 are formed integrally, and an air supply tube 460a, awater supply tube 460b and the forceps channel tube 471 are formedindependently. In FIG. 35B, the forceps channel 403 and the outer covertube 406 are formed integrally, and the air supply tube 460a, the watersupply tube 460b and the insertion section inserting channel 470 areformed independently.

Moreover, in FIG. 35C, the forceps channel 403, the air supply tube460a, the water supply tube 460b and the outer cover tube 406 are formedintegrally, and the insertion section inserting tube 470 is formedindependently. In FIG. 35D, all the channels are formed integrally withthe outer cover tube 406. In FIGS. 34A to 34D it is possible toconstruct the air supply tube 460a and the water supply tube 460b as onechannel. Further, various multilumen constructions can also be used.

What is claimed is:
 1. A protection cover for use in an endoscope systemincluding an endoscope having an insertion section insertable into acavity under inspection and an operation section to which a proximal endof the insertion section is connected and a protection cover having aninsertion section cover for covering said insertion section of theendoscope and an operation section cover for covering said operationsection of the endoscope, the improvement being characterized in thatsaid operation section cover comprises a first cover portion forcovering a grip portion of said operation section and made of rigid orsemi-rigid material and a second cover portion for covering theremaining portion of the operation section of the endoscope and made ofsoft material.
 2. A protection cover according to claim 1, wherein saidcover is disposable.
 3. In a protection cover for use in an endoscopesystem including an endoscope having an insertion section insertableinto a cavity under inspection and an operation section to which aproximal end of the insertion section is connected and a protectioncover for covering said endoscope, the improvement being characterizedin that said protection cover comprises an insertion section cover forcovering said insertion section of the endoscope, a connection portionhaving a first end connected to a proximal end of said insertion sectioncover and for covering a grip portion of the operation section of theendoscope, an outer cover having a first end connected to a second endof the connecting portion and an opening formed in a second end of saidouter cover, a means for closing said opening of the outer cover in sucha manner that said opening can be opened, and a means for (i)maintaining said opening of the outer cover in an opened condition suchthat the endoscope can be easily inserted into the outer cover throughsaid opening and (ii) fixing an outer periphery of the opening to theendoscope, wherein (i) said insertion section cover and connectingportion are surrounded by said outer cover and (ii) said opening of theouter cover is closed before usage.
 4. A protection cover according toclaim 3, wherein said means for maintaining said opening of the outercover in the opened condition comprises a resilient member having ametal wire embedded therein.
 5. In a protection cover for use in anendoscope system including an endoscope having an insertion sectioninsertable into a cavity under inspection and an operation sectionhaving at least one operation switch, said operation section beingconnected to a proximal end of said insertion section, said protectioncover having an insertion section cover for covering said insertionsection of the endoscope and an operation section cover for covering andsurrounding said operation section of the endoscope, the improvementbeing characterized in that said operation section cover is constructedto cover said operation section of the endoscope in an airtight mannerand includes at least one switch provided in an outer surface of theoperation section cover.
 6. A protection cover for covering anendoscope, the endoscope having an insertion section and an operationsection connected to one end of the insertion section, said covercomprising:an insertion section cover for covering the insertion sectionof the endoscope; and an operation section cover for covering theoperation section of the endoscope and comprising (i) a first coverportion, for covering a first portion of the operation section of theendoscope, formed of a material having a first rigidity value, and (ii)a second cover portion, for covering a second portion of the operationsection of the endoscope, formed of a material having a second rigidityvalue, said second rigidity value being less than said first rigidityvalue.
 7. A cover according to claim 6, wherein said cover isdisposable.
 8. A protection cover for use in an endoscope systemincluding an endoscope having an insertion section insertable into acavity under inspection and an operation section having a grip portionand at least one electric switch, said operation section being connectedto a proximal end of said insertion section, said protection coverhaving an insertion section cover for covering said insertion section ofthe endoscope and an operation section cover for covering said operationsection of the endoscope, said operation section cover comprising a gripcover made of elastomer so as to be capable of tightly covering saidgrip portion of the operation section of the endoscope and said electricswitch being exposed outside the protection cover so as to be accessibleby a user outside said protection cover.
 9. A protection cover for usein covering an endoscope having an insertion section insertable into acavity to be inspected and a operation section connected to a proximalend of the insertion section, said cover comprising:an insertion sectioncover for receiving therein the insertion section of the endoscope; andan operation section cover for receiving therein and surrounding theoperation section of the endoscope and comprising at least one switch,for performing a predetermined operation, which can be selectivelyoperated by an operator.
 10. In a protection cover for use in anendoscope system including an endoscope having an insertion sectioninsertable into a cavity under inspection and an operation section towhich a proximal end of the insertion section is connected, saidprotection cover being for covering said endoscope, the improvementbeing characterized in that said protection cover comprises an insertionsection cover for covering said insertion section of the endoscope, anoperation section cover for covering said operation section of theendoscope and being made of soft material, and a grip portion cover forcovering a grip portion of the operation section and being made of hardor semi-hard material.
 11. A protection cover according to claim 10,wherein said operation section cover made of soft material is coupledwith said insertion section cover to form a single integral body.
 12. Aprotection cover according to claim 10, wherein said grip portion covermade of hard or semi-hard material comprises one of a plurality of gripportion covers having different shapes from each other.